The proposed research will investigate the development of two aspects of the human visual information-processing system. One portion of the research will determine the relative duration of iconic storage (brief "sensory memory") in elementary school children and adults; another segment, using the same age groups, will ascertain the speed with which central processing mechanisms can (a) transfer information from iconic storage to more permanent memory and (b) perform high-speed "scanning" or comparisons in memory. At least six experiments, all using briefly-presented visual stimuli, will provide several different approaches to these issues. Among the techniques to be used are post-stimulus cueing, backward masking, dark interval detection, and temporal summation of successive stimuli. Some of these methods will be used developmentally for the first time; others will feature improvements of the techniques used in earlier developmental studies.